Piezoelectricity is the voltage generated over some materials, e.g. some crystals, when they are subjected to mechanical deformation. Conversely, a voltage applied over the material causes a mechanical deformation of the material. It is well known to use this piezoelectric principle in many applications, such a piezoelectric pressure sensors, microphones, loudspeakers, actuators, and other transducers.
An example of a piezoelectric transducer device, namely a piezoelectric speaker, is disclosed in GB1310853. The piezoelectric speaker in GB1310853 includes a circular piezoelectric element mounted on a thin circular diaphragm. The thin circular diaphragm is supported at its circumference on a supporting member, which is a portion of a housing, and clamped tight by a tightening member. In one embodiment, annular members of resilient material are respectively disposed between the thin diaphragm and the supporting member and tightening member, to damp the circular diaphragm. However, in this solution, means are required to fasten the tightening member to the supporting member, complicating the construction and assembly of the speaker.